This invention relates to a system which can be subjected to remote control by a voice command signal, and more particularly to a voice responsive remote-controllable system suitable for application to, e.g., a terminal answering device, etc.
By taking an example of a terminal answering device, the prior art will be first described.
When there is a call incoming, a conventional terminal answering device automatically responds to that call incoming to transmit an outgoing message (hereinafter referred to as an OGM). After the OGM has been transmitted, the terminal answering device then records an incoming message (hereinafter referred to as an ICM) from a calling subscriber. However, when a multi-frequency (MF) signal is transmitted from a calling subscriber during transmission of OGM, the MF signal detector detects this MF signal. As the result of the detection, where that MF signal is in correspondence with an MF signal determined in advance (e.g., "* dial"), this terminal answering device stops transmission of OGM and is then placed in a detection mode for an identification code (ID code).
An ID code is registered in advance into this terminal answering device by an owner thereof, and is expressed as a code train comprised of a plurality of dial numbers (e.g., "1, 2, 3").
After this terminal answering device is placed in the detection mode for ID code, when a MF signal train is transmitted from a calling subscriber, the MF signal detector detects this signal train to compare the detected result with an ID code registered in advance. If that detected result is in correspondence with the registered ID code, this terminal answering device transmits an audible sound for allowing the calling subscriber to confirm that this terminal answering device has accepted that ID code. In contrast, where the above-mentioned detected result is not in correspondence with the registered ID code, this terminal answering device transmits for a second time an audible sound for requesting the calling subscriber to transmit a MF signal train.
When the ID code is accepted, this terminal answering device is placed in a command standby state. At this time, where a MF signal transmitted from the calling subscriber is in correspondence with a command determined in advance, this terminal answering device is placed in an operational mode corresponding to that command. Such commands are MF signal trains determined in advance which correspond to the operational modes of the device with a one to one correspondence relationship. This relationship is determined in a manner that, for example, command "#1" corresponds to an ICM playback operation, command "#2" corresponds to an OGM recording operation, and command "#" corresponds to a stop operation.
When it is assumed that an MF signal train "#1" is transmitted from a calling subscriber in a command standby state, a PB signal detector detects this signal train to make a comparison as to whether that signal train is in correspondence with a command determined in advance. In this example, since that signal train is in correspondence with the command "#1", playback of ICMs recorded in the past is initiated. When it is then assumed that an MF signal "#" is transmitted from a calling subscriber during playback of ICMs, detection/comparison are similarly conducted to stop playback of ICMs. Thus, this terminal answering device is placed in a next command standby state.
In this way, this terminal answering device is subjected to remote control by MF signals.
As stated above, in a remote controlled system such as a conventional terminal answering device, MF signals are used as ID codes or commands. For this reason, in order to conduct remote control of such a system, equipment such as, for example, a telephone system for an MF line having a function to transmit MF signals must be used. Namely, conventional equipment cannot be subjected to remote control from equipment such as, for example, a telephone system exclusive for a DP line which does not have a function to transmit MF signals.